Picture projecting device



April 18, 1961 J. M. MILLER PICTURE PROJECTING DEVICE Filed March 28, 1957 IN VEN TOR. z/AcK /l I MILLER BY HAS ATTORNEYS.

United States Patent Qflice g 2,979,986 PICTURE PROJECTING DEVICE Jack M. Miller, Chicago, Ill., assignor to Paromel Electronics Corp., Chicago, Ill.

Filed Mar. 28, 1957, Ser. No. 649,107 1 Claim. (CI. 88-24) This invention relates to a picture projecting device of the general character for projecting a picture or symbol upon a screen. The invention has as. one of its objects'the provision of an improved construction of the character hereinafter described which will be simple, compact, economical in manufacture and highly eflicient in use.

Another and equally important object of thisinvention is the provision in a picture projecting device of an eflicient and effective arrangement for ventilatingthe device thereby to preserve and maintain at an even and proper temperature such parts of the apparatus as are generally subjected to undue heat normally generated by the lamp within the projecting device.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will bebest understood by reference to the accompanying drawings showing the preferred form of construction, and in whichr Fig. l is a perspective view of the invention;

Fig. 2 is a sectional detailed .view on line 2-2 of Fig. 1;

Fig. 3 is a sectional detailed view on line 33 of Fig. 2;

Fig. 4 is a sectional detailed view taken substantially on line 44 of Fig. 2.

For the best results, successful operation and economical manufacture, I accomplish the several objects ofmy invention by the-preferred, form of construction shown in the drawings which construction will now be explained.

The structure preferably employed-by me to accomplish the several objects of my invention comprises a box-like body including end Walls/11, side walls 12, top wall 13 and a removabl'ebottomwall 14.

Extending upwardly from one corner of thetop'wall 13 is a post15 having adjustably and slidably positioned thereon, a mounting 16 carrying a projection lens within a barrel 17. The bracket 16 is slidable on the post 15 and is 'fixed in an adjustedj'position with respect to such post 15 by a finger bolt '18.

Mounted on the barrel 17 isa hood 19 consisting generally of a reflector inth'e form-of a reflector mirror 20, arranged at an inclination with respect to ,a horizontal line.

The top wall 13 has an opening 21 formed therein of substantially rectangular or square formation. Mounted in any suitable manner upon the top wall 13 over the opening 21 is a transparent work plate 22.

Adjacent opposite ends of the body 10 are transversely extending compartments 23. Each compartment 23 has a hinged door 24. In such compartment are arranged rollers 25 and 25 each independently rotated by means of hand cranks 26', Fig. 1. The roller 25 is adapted to carry a roll of transparent paper 26, the web of which is paid through a slot 27 from which it taken substantiallytaken substantially 10, in an inclined position wall thereon, is a mounting which abuts the wall 31 of the adjacent compartment, 23. The lower end portion 32 terminates short of the bottom Wall 14 to provide a space 33. This plate maybe mounted in any suitable manner within the body, as for example, upon supporting flanges 34 secured to opposite side walls 12 of the body 10. The opposite lower corner portions of the plate 30 are tapered to provide open spaces 35.

Mounted upon the plate 30 and in a position directly below the opening 21 is a reflector mirror 36 in operative relation to the lens of the barrel 17.

Disposed beneath the work plate 22 and in close spaced parallel relation with respect thereto is a plastic lens 37 of a size substantially equivalent'to, or slightly larger than the opening 21.

Arranged vertically in the body at one end thereof is a partition 38. This partition divides the body into a lamp compartment 39 and a compartment 39' which houses the reflector mirror 36 and the plastic lens 37.

It is desired that the work plate 22 be hinged to the top wall as at 22. The plastic lens 37 is hingedly connected as at 37 to support flanges 56 carried by the side walls 12 of the body 10. As such the interior of the body 10 is easily reached by simply pivoting both the work plate respective hinged connections.

Positioned in this compartment 39 is a lamp housing 40 within which is a lamp 41 forwardly of a concaved reflector 42, carried by a movable panel 42'. Forwardly of the lamp 41 and carried by the partition 38 is a glass condenser lens 43 positioned within the compartment 39'. The lens 43 is operatively'related to the reflector mirror 36.

Light from the lamp 41 by the condenser lens 43, Will be projected upon the reflector mirror 36, from, which mirror the light is projected through plastic lens jected upon the reflector, mirror 20 and, from thenceupon the screen.

Invariably, considerable heat is generatedwithin the body 10 by the lamp filamentwith the result thatif means is not provided fordissipating, such heat, the

parts, such for example, the plastic lens 37 will become,

distorted, warped and often ruinedv beyond use, andthe' reflector mirror might be cracked'or broken.

To overcome thisundesirable condition which exists in the present day picture projection apparatuses, 1 pro-,

vide in the body 10 a motor 44 which operates anAexhaust fan 45 and an intake blower 46. The exhaust fan 45 has an outlet opening,47,.which is formed in.

the adjacent side wall 12, of the body 10, Fig; ,4. I

Formed in the oppositeside walls'12'of thebody' 10, below the upper edge portion thereof in close proximity to the plastic lens 37 are elongated slots 49, of which there may be two or more in each side wall. The front wall 11 of the body 10 is provided with an opening 49 which has communication With the space between the Work plate 22 and plastic lens 37 as viewed in Figs. 2 and 3. As such, air may be admitted into the interior of the compartment 39' by passing through the opening 49' and passing between the work plate 22 and plas- 22 and the plastic lens 37 about their tic lens 37, as well as passing through the elongated slots 49 formed in the side walls 12.

When the motor 44 is operative, outside air is drawn into the body through that slots 49 beneath and across the plastic lens 37 into the interior of the body 10 to be exhausted therefrom from the lower portion thereof, by the exhaust fan 45, through the exhaust opening 47.

By this arrangement, outside air is continuously circulated through the compartment 39 by the exhaust fan 45 while at the same time hot air from within the lamp housing compartment 39 is being expelled therefrom by the blower 46, the latter being accomplished in the following manner:

The blower 46 communicates with a screen intake opening 50 formed in the adjacent end wall 11. Com municating with the blower 46 as at 51 is a conduit 52 which in turn has communication with a box like duct 53 arranged within the body 10 adjacent the bottom wall thereof. This duct 53 communicates with the compartment 39 and with the lamp housing 40 at their lower end portions.

In the adjacent wall 11 of the body 10 is provided a screened exhaust opening 54 through which is expelled the hot air from within the compartment 39 and the lamp housing 40 by the blower 46.

Adjacent the lamp 41 oneach side thereof and in the path of incoming air from the duct 53 is a curved deflector plate 57 which is related with respect to the lamp 41 in a manner such as to direct the outside air from the duct 53 upwardly along the opposite vertical sides of the lamp 41.

The lamp housing at its upper end portion provides a rearwardly extending opening 58 which is arranged in spaced relation with respect to the exhaust opening 54 and through which the hot air from the lamp housing 40 is expelled.

Between the lamp housing 40 and the side walls 12 of the body '10 are relatively flat elongated baflle plates 59 which also extend over and in spaced relation to the top of the lamp housing 40. These plates act to prevent radiation of heat from and about the lamp housing 40 and which will also provide aninsul-ated air space 60.

When the blower 46 is in operation, outside air will be drawn through the opening 50 and be forced through conduits 52 and 53 by the blower 46 into the lamp housing 40. As the outside air enters the lamp housing 40, hot air will be expelled from about the lamp housing 40 and from within the compartment 39, through the exhaust opening 54. The deflecting plates 57' will serve to deflect outside air upwardly through the lamp housing along the opposite vertical longitudinal sides of the lamp 41 thus maintaining such lamp 41 at a proper temperature. As the outside air enters the lamp housing 40, it will also pass through the space 61 and out an opening 61 formed in the bottom of the movable panel 42 of the.

lamp housing 40 and thence pass upwardly through the space 40' between the lamp housing and the exterior end wall 11.

By the foregoing arrangement, during the operation of the blower 46, hot air is continuously expelled from the lamp housing 40 and the compartment 39 which housesit thus maintaining the same at a desirable temperature while at the same time extending the life of the lamp. During such expulsion, coolair is continuously circulated throughout the compartment 39' by blower 45.

Such latter arrangement is especially desirable not only from the standpoint of protection of the lenses and reflector mirror but also because of the fact that in writing or drawing upon the transparent paper on the work plate 22, the hand will normally rest thereon and for that reason it is desirable that the work plate be maintained cool or at a comfortable and safe temperature.

Drawing cool air into the body 10 for passage between the work plate 22 and the plastic lens 37 and throughout the compartment 39' assures protection of the plastic lens preventing the same from warping or otherwise becoming distorted or discolored.

While I have illustrated and described the preferred form of construction for carrying my invention into eflect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claim.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

An improvement in a picture projector in which the projector includes a box-like body having a partial open top, the improvement comprising a partition adjacent one end of the body for dividing the body into a lamp housing and an open top lens and reflector compartment, said compartment being normally closed by a hinged work plate and a hinged lens carried by said projector and arranged in parallel spaced relation with respect to each other, an exhaust fan within said compartment and having open communication therewith, a blower within said compartment and having communication with an inlet opening formed in one end wall of said body, an air duct communicating with said blower and extending through said compartment and terminating in open communica tion with said lamp housing adjacent the bottom wall thereof, deflector plates provided by said duct within said lamp housing and disposed in the path of air moved therethrough by said blower so as to deflect a portion of the air upwardly about the lamp, an air outlet' formed in the other end wall of said body for said lamp housing adjacent the top thereof, and an air inlet formed in said one end wall of said body having communication with said compartment through the space between said spaced apart plate and lens for circulating outside air therebetween andthrough said compartment by said exhaust fan.

References Cited in the file of this patent UNITED STATES PATENTS 1,262,180 Davies Apr. 9, 1918 1,545,674 MacKay July 14, 1925 1,929,776 Faber Oct. 10, 1933 2,014,840 Geiger et al Sept. 17, 1935 2,120,005 Scott June 7, 1938 2,281,988 Osterberg et al May 5, 1942 2,294,219 Woermann Aug. 25, 1942 2,362,601 Wengel Nov. 14, 1944 2,395,561 Osterberg et al. Feb. 26, 1946 2,413,288 Cahill Dec. 31, 1946 2,434,193 Brenkert Jan. 6, 1948 2,449,713 Nemeth Sept. 21, 1948 2,564,057 Fitzgerald Aug. 14, 1951 2,802,284 Dreisonstok et a1 Aug. 13, 1957 2,817,267 Halahan et al. Dec. 24, 1957 

